1. Field of the Invention.
The invention in general relates to appliance timers and in particular to a dryer timer.
2. Description of the Related Art.
Electromechanical timers have been used to provide programmed control of appliance functions for more than half a century. Such timers generally comprise a motor-driven cam and electrical switches responsive to the cam for controlling the appliance functions. The cam and switches are mounted in a timer housing, and electrical terminals connected to the switches extend from the housing. Generally, the timer also includes electrical busses which connect some of the terminals in order to distribute the electrical power and timing signals appropriately for the timing function and to provide for more efficient connection to the appliance components to be controlled by the timer. In dryer timers, the bussing comprises individual terminals being connected by bussing strips or wires. See for example FIG. 1 of U.S. Pat. No. 4,381,430. In washer timers, the current loads are smaller and the number of terminals are larger. For efficiency, the terminals are generally located in groups, such as in a bussing block, and bussing is by primary busses that are common to several terminals passing along or between a row or column of terminals and secondary busses that connect the primary busses and individual terminals where desired. See for example U.S. Pat. Nos. 4,567,654 on an invention of Ernest F. Kloenne and Garry A. Stout; 4,517,426 in the names of James O. Edwards and Charles Malone; 3,809,831 in the names of George A. Godwin and William E. Wagle; 3,771,102 on an invention of Stephen F. Murray and Harold T. Simmons; and 3,390,243 in the name of George Obermann. The bussing systems described in the above patents all have the characteristic that in order for the bussing to be flexible, potential connection paths exist between all terminals and the primary busses between terminals. Thus if the terminal is not connected to a primary bus that passes it, an air gap exits between the terminal and the bus. Since there are many terminals together in a bussing block and such blocks are desirably compact, these air gaps are small and in dryer timers that carry large power loads current leakage or arcing can occur. Other patents which applicant is aware of that relate to bussing are U.S. Pat. Nos. 3,571,779 in the name of John Covell Collier; 3,353,138 in the name of W. W. Loose; 3,212,048 in the names of R. A. Rosenberg and M. A. Mittler; and 3,208,028 in the names of M. A. Mittler, S. Offerman, A. B. Pittmann, and R. A. Rosenberg. These appear to relate to computers which operate at significantly lower power loads than timers and all have the same disadvantages of the above-cited washer bussing devices, but more so.